package com.young.security;

import java.io.PrintWriter;
import java.io.StringWriter;

/**
 * 关于异常的工具类.
 *
 * @author calvin
 */
public class Exceptions {
  
  /**
   * 将CheckedException转换为UncheckedException.
   */
  public static RuntimeException unchecked(Exception e) {
    if (e instanceof RuntimeException) {
      return (RuntimeException) e;
    } else {
      return new RuntimeException(e);
    }
  }
  
  /**
   * 将ErrorStack转化为String.
   */
  public static String getStackTraceAsString(Exception e) {
    StringWriter stringWriter = new StringWriter();
    e.printStackTrace(new PrintWriter(stringWriter));
    return stringWriter.toString();
  }
  
  /**
   * 判断异常是否由某些底层的异常引起.
   */
  public static boolean isCausedBy(Exception ex, Class<? extends Exception>... causeExceptionClasses) {
    Throwable cause = ex;
    while (cause != null) {
      for (Class<? extends Exception> causeClass : causeExceptionClasses) {
        if (causeClass.isInstance(cause)) {
          return true;
        }
      }
      cause = cause.getCause();
    }
    return false;
  }
}
